A conventional slide switch is disclosed in Japanese Utility Model Laid-Open No. 50-23681. This prior art device prevents a movable contact from disengaging within a slide switch which performs its switching operation by pivotal movements of its movable contact. In this regard, the switch of the Japanese Utility Model No. 50-23681 is especially characterized by a movable contact having a semilunar or V-shaped tabs at the center of both sides thereof, a movable contact receptacle on which the movable contact is placed and formed of a thin elastic plate having an acute angle, a bent surface formed at a cutout portion on opposing erected surfaces and a slant surface formed at the upper portion of the erected surfaces. The receptacle thus holds the movable contact.
The above-mentioned prior art slide switch is intended to prevent the movable contact from dropping by holding the movable contact within the conductive receptacle. The movable contact is a slide switch which pivots on the conductive receptacle so as to swing when its knob is moved left or right, thereby making or breaking a circuit with the fixed contact.
As a result of such structural relationship, current flows through many contact portions--for example, a clamping terminal, a conductive receptacle, a movable contact, a fixed contact, a clamping terminal, a lead, a load and then on to the other pole of the power source. Therefore if it is used with a current route carrying large current at even a relatively low voltage, the result will be high heat due to Joule heat produced by the contact resistance at the contact portions or the clamping portions of the clamping terminals.
In addition, such a prior art switch results in a high manufacturing cost because of its complicated configuration which involves a number of parts and clamping processes affecting the efficiency of assembly.
It is therefore the objective of the present invention to eliminate several components associated with prior art slide switches thereby simplifying the same. In this regard, the present invention is embodied in a slide switch having fixed conductors comprised of plural narrow conductive plates (i.e., so called bus bars), metal tubes or conductive rods in parallel. A switch which makes an electrical circuit between the fixed conductors is provided with a movable conductor element (preferably a conductive ball) which may be moved into the gaps between an adjacent pair of fixed conductors. As a result, electrical contact between the movable conductor element and the fixed conductors is made with the latter being astride the former.
An insulated sliding body is slidably mounted in an interior cavity formed within an insulated support housing having a substantially inverted U-shaped interior cross-section. The sliding body carries a spring-biased movable conductor (preferably a conductive ball) which is adapted to contact the fixed conductors extending transversely across a lower portion of the insulated support housing. The plural fixed conductors are preferably mounted in parallel to one another by means of paired grooves formed on a lower edge portion of the insulated support housing. Thus, by providing plural cylindrical conductive tubes, rods or plates in longitudinal arrangement as fixed conductors for the slide switch, a section of the knob-operated movable conductor will be brought into the gaps between the fixed conductors. In addition, since the movable conductor is spring-biased, it will forcibly be brought into the gaps between a pair of fixed contacts in a snapping action by virtue of the spring, thereby making a circuit with the fixed conductors in contact therewith at both sides to turn on an electrical load. The elastic "snapping" action of the spring-biased knob-operated movable conductor into the gaps between the fixed conductor provides the knob operation with a beneficial click-type action.
Manual movement of the movable conductor breaks electrical contacts with the pair of fixed contacts thereby turning off the electrical load. The switch thus serves as a single pole dual position switch or a double pole dual position switch if the movable conductor is then brought into contact with another pair of the fixed conductors.
Further, since the conductive tubes, conductive rods or conductive plates used as fixed conductors may be integrally formed with a narrow conductive plate (i.e. the bus bar), the fixed conductors can be connected directly to another electronic component or a circuit pattern via the bus bar. As a result, no clamping portion or lead is required.